System and Method of Registering with an Access Point

Abstract

A method of registering a mobile device with an access point, is provided in which the mobile device preregisters with access points nearby in order to accelerate the registration process when roaming is initiated. Roaming may be initiated when the SNR is increasing relative to the current access point and decreasing relative to another access point.

Description

[0001]This application claims the benefit of U.S. provisional application No. 60 / 687,339, filed on Jun. 6, 2005.FIELD OF THE INVENTION[0002]This invention relates to systems and methods of managing data traffic over networks, and more particularly to systems and methods for addressing the diverse requirements of different data types and their behaviour over different types of wired and wireless networks, each such network having different characteristics and changing network status.BACKGROUND OF THE INVENTION[0003]Wireless networks generally have very different properties when compared to traditional wired networks. For example, the “backbone” of a wired network is more homogeneous than a wireless network, and a wired network is typically, a mesh of intelligent sub networks connected through routers and switches that control data traffic. In wired networks, users are generally stationary and therefore movement of users has little impact on network service. The key influence on user ...

AI Technical Summary

Benefits of technology

[0029]The system and method according to the invention makes the mobile device aware of the network situation and application types and therefore their requirements; and also is aware of network policies at any given time, and therefore can make efficient decisions. The necessary “intelligence” is available so that there is no need to alter “any” application, the mobile device's Operating System (OS) code structure, or hardware. The solution is such that the network works with or without the system according to the invention (but the network is more efficient with such system) and other mobile devices not using the system can operate within the network. This is accomplished by adding the capability to the mobile device's OS to intercept system calls and alter the calls without initiator and destination involvement.

[0031]Thereby, the system according to the invention:i) delivers greater bandwidth efficiency and network capacity by managing all data types over single and mixed networks by taking a protocol approach, thereby reducing the overhead created by extra connections established by applications in the wireless network (only one connection is required) and reducing the overhead of data being transmitted by reducing the required acknowledgements, sending only non-expired data and filtering out others, and not using inefficient TCP / IP spoofing and tunnelling techniques;ii) increases overall quality of service by using an efficient protocol designed specifically for wireless networks and able to work with all data types (not just “background” data types). By tying directly into the TCP / IP command structure in the upper layer on a mobile device (or other networked device) a protocol is created; and by providing efficient prioritization, queuing, and scheduling of different data types a superior experience for applications such as VoIP, interactive gaming and streaming video is provided, along with email and corporate applications; andiii) provides better network reporting and an integration strategy for carriers supporting multiple networks (mixed networks). As there is a client component within the system, a carrier can now observe their network end-to-end, treating the mobile device like a network element, enabling the carrier to support stronger Service Level Agreements (SLAs) and service quality assurance. Furthermore, the information about network and application status and performance is included as part of the same protocol which delivers the data and therefore obviates the need for extra transactions or scheduled tests to determine the status and performance of the network. Also, the carrier can observe what is on the client's device, including software and mobile device configurations, thereby allowing the carrier to address service issues in a timely fashion, reducing both costs and customer frustration. As the network information is transmitted to a server component, as part of the data protocol delivery, the carrier can receive extensive reports on network status, bringing full visibility of the network to the carrier. The lower layer component of the system, according to the invention, on the mobile device enables seamless switching or simultaneous use of multiple network technologies (e.g. between cellular 2.5G / 3G / 4G, Wi-Fi and WiMAX) which could be based on usage policy, application type, and / or network policy. This allows the carrier to provide their customers multiple network choices, using the choice that best satisfies their user's requirements without having to concern themselves on how to use the networks, or when to switch to the networks without interrupting the user or the application. This also provides greater network efficiency for the carrier by allowing the carriers to use faster networks for backhaul transport, e.g. Wi-Fi for music downloads, and the more expensive cellular networks for email and other data applications.

Problems solved by technology

1. The network infrastructure of a wireless network is simpler, with respect to the number of nodes between a mobile networked device and a first wired link in the network.

2. The status of a wireless network changes frequently, due to several factors, including: environmental conditions (e.g. downtown urban area vs. suburban area with different signal attenuation and propagation); mobile device location (e.g. close to a large power supply field vs. in a large open area); network traffic at a given time, adjacent user usage of the network; and the base station backbone (e.g. fiber vs. copper backbon

3. Software applications are generally not designed for wireless network environments that include frequent status variation. Therefore, operating such applications over a wireless network may worsen the network status by adding additional traffic, and thereby increasing the overall delay and latency of the network, which, in turn, may impact the experiences of other mobile device users.

However, use of these different types of applications results in different data traffic types traversing the network, each data type having different delivery (time) requirements and different error tolerances (in time sensitive vs. error sensitive spectrums of applications).

For example, a VoIP packet is very time sensitive and has a short time to live, whereas a data packet is very error sensitive.

TCP does provide congestion control features which occur on wired networks but the protocol doesn't distinguish a wired network from a wireless network.

However, use of TCP / IP over wireless networks may be problematic.

For example, delays in the wireless network may be caused by signal attenuation (not by congestion), causing TCP / IP to actually reduce performance of a wireless network.

Therefore, what is lacking in the prior art is the awareness and involvement of the networked (for example, mobile) device in the network by enabling the networked device to act as an intelligent and integrated element (similar to a router / switch) within the network.

1. TCP / IP inefficiency over wireless networks;

2. the lack of knowledge of wireless networks within the protocol layer of networked devices;

3. VoIP and the standard streaming video control protocol, known as the Real-Time Transport Control Protocol (RTCP) inefficiency over wireless networks;

4. the inability to dynamically distinguish between the different types of data and meet their real-time requirements in a mixed network, without relying on IP header information;

5. the inability of a mobile device in a mixed network to be aware of the types of the available networks and the status of each network at any given time and to feedback status information to the network as part of the data protocol delivery without requiring any extra transaction;

6. the inability of a mobile device in a mixed network to predict the signal to noise ratio (SNR), outside the physical layer and below the IP layer, of the wireless network and to make decisions for appropriate traffic types, such as forwarding / redirecting traffic through different networks, or using two types of networks simultaneously based on their conditions and network policy;

7. the inability to provide local jitter handling within a mobile device in the layer below IP; and

8. the inability to provide mobile data traffic prioritization, queuing and scheduling within a mobile device, based on the network condition and policy, or through either DNA / fingerprints set by a catalogue ID or determining the application type.

These solutions include using TCP / IP spoofing and tunnelling techniques that are inefficient and often cause yet more unnecessary data to be sent over the wireless networks, and produce extra processing overhead for the network device.

In a wireless network, the failure to receive an acknowledgment within a given time is usually not due to congestion but due to instant network delays, signal strength drop, or latency variation.

In such situations a TCP / IP node will slow down the transmission and take some time before returning to its normal speed of operation.

During this time the throughput over the same bandwidth will be reduced because of the unnecessarily slowed transmission.

Another problem caused by TCP / IP is that it was designed for the low bit error rate link environment of a wired network and therefore if one packet within a stream of packets is lost then all packets are resent.

All of these communications create extra overhead and add delay to a wireless network.

To solve these problems there have been several inefficient solutions, which focus on a single type of data, using applications such as Internet Explorer.

To date, none of these approaches have been entirely adequate.

Although this method reduces the amount of data travelling over the network, which indirectly results in greater use of bandwidth, it does not eliminate TCP / IP inefficiencies over wireless networks, as it is the wireless delay variations that cause the strange behaviour of TCP / IP.

This technique reduces the need for transferring frequently requested queries but it does not address TCP / IP inefficiency directly.

The disadvantages of this technique include:(i) Process consumption.

This means that more processing time will be required for a small mobile device and further delays will be caused by the tunnelling technique.

Also, if the compression or encryption happened in the layer 4 (above TCP and UDP layers and below the application layer) then the proxy-type may not be able to distinguish the type of application.(ii) Increased network traffic.

This “solution” does not solve the TCP inefficiency issues created by the wireless network's latency variation, as TCP data has already been created but is wrapped around a different protocol for transmission.

However, if the network has high latency, TCP would still result in strange behaviour due to lack of receiving responses in a timely fashion.

This approach also increases the traffic over the wireless network by adding unnecessary data and also changes the mechanism of new packet switched networks to that of the old legacy circuit switch networks.

This results in a lower network capacity and inefficient use of the network.

For time-sensitive applications, this results in additional delay caused by the movement from one AP or domain to another.

A problem in the art is in resuming an application session and this has not been specified in any standard.

It has been suggested that the Mobile IP standard within a network could solve the problem, but the amount of signalling traffic within Mobile IP creates too much unnecessary traffic.

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